Oh I can so see how this incident, and particularly this conversation with his father, would color Giles' relationship with his slayer. To her benefit I believe. A little peek in at Giles' young life, before the expectation of the mantle of watcher entered in was a nice bit too. In a way, the story carries it's own duality, Giles before he knew anything about watchers and slayers and a conversation with his father that, ultimately, was all about them.